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(meteorobs) NAMN Notes: April 2002
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NAMN Notes: April 2002
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Introduction:
NAMN Notes is a monthly newsletter produced by the North American Meteor
Network, and is available both via email, and on the NAMN website at:
www.namnmeteors.org
Contents:
1. International Astronomy Day!...
2. Info Sheets for Clubs and Events...
3. April Lyrids...
4. Other Spring Showers...
5. Upcoming Meetings...
6. For more info...
1. International Astronomy Day!...
Saturday April 20th is International Astronomy Day, and astronomical groups
around the world are encouraged to get out and help spread the word about
astronomy!
Why is Astronomy Day so important? It is a wonderful opportunity to help
spread the word about astronomy in general, and in our case, meteor
astronomy in particular, to people who otherwise might not have the chance
to talk to someone directly involved in active observing. Astronomy Day
helps provide them with information both on what is out there to observe,
and the many ways to do it - by means that are visual, telescopic,
photographic, video, radio or otherwise.
Talking to the public gets the information out to a wide audience in terms
of age - from young children, to teenagers, to adults, to seniors. Some may
have Internet access - and some may not. Some may be interested in the
technical aspects, and the high tech astronomical equipment on the market
today - and some may just want info on what they can observe from their
lawnchair up at their cottage in the summer. Astronomy Day gets real people
out talking to others wanting to find out more about our interest in
astronomy!
What can we in the meteor community do this year to help out with
International Astronomy Day? Here are some suggestions:
- If you have a local astronomy club in your area, volunteer to help them
out with their Astronomy Day activities... print off some of our NAMN
brochures and info sheets, and take them along with you to hand out to the
public...
- Offer to give a short talk on meteors or meteorites to your children's
science class... wear a colorful astronomical t-shirt, take in some bright
posters on space... print off some star maps for the kids... and talk about
what you like to observe!
- If you don't have kids, get in touch with your local scout group, and
offer
to talk about meteors and space... again, take some posters or show some
slides... and give the kids some star maps and meteor shower information
to take home with them...
- Phone up your local bookstore, and encourage them to put out a special
display of books on astronomy and how to explore the sky... tell them that
it's International Astronomy Day on April 20th!
- Phone up your local library, and encourage them to put out a space
display... with books from their astronomy section... both from the adult
and children's sections...
- If you have an observatory or museum near where you live, talk to them
about International Astronomy Day, and offer to help with a display on
meteors and observing... or even just provide them with some NAMN handout
material to give out to their visitors...
- Contact a local shopping mall, and see if you can do a display in the
mall... or outside, in their parking lot! To help spread the word about
astronomy, it is important to go to where the people are! Set up a table
with some astro books and free handout material, some colorful space posters
on easels, and a telescope or two. Wear something bright and astronomical!
If you are with a group, a display can be even larger. People love this
stuff... and even if they themselves are not interested, you will always get
people picking up information for a friend, or grandchild! For ideas for a
'sidewalk display' check out Pierre Martin's OAOG's group activities for
Astronomy Day last year at www.oaogdot ca/StarpartyPictures/StarParties.htm
This Canadian co-author helped out with the day and night activities, and we
handed out lots of info on meteor showers!
What handout material is available for Astronomy Day activities?
- We can provide a meteor brochure and other information sheets as handout
material for your Astronomy Day activities, club events, and summer star
parties! To obtain copies, simply email Mark Davis at meteors@comcastdot net.
You can then print these on white paper, or get some brightly colored paper
to use!
- Print off free star maps from one of the astro websites! A good site for
a single 'whole sky' star map is Heavens Above: www.heavens-above.com
- Go to the website of the International Dark Sky Association, and print off
some of their handout material on better lighting for your health and your
astronomy! www.darksky.org Several interesting IDA handouts are:
'Return of the Night' by H.G. Graham
http://www.darksky.org/ida/infoshts/pdf/is107.pdf
'Light Pollution - Theft of the Night'
http://www.darksky.org/ida/infoshts/is090.html
And - if you have any other favorite astro web sites, print off some
information from them as well. Many sites now have information for those
just beginning in astronomy. This makes great handout material.
Kids and adults alike are taking more of an interest in science and
astronomy today than ever before. If we, as meteor observers, can help in
any way to spark their imagination, then we are doing a service both to the
astronomical community in general, and to the meteor observers of tomorrow!
Happy Astronomy Day 2002!
2. Info Sheets for Clubs and Events...
To help spread the word about meteors to the public and to beginning
observers, NAMN has recently prepared some special info sheets that can be
handed out to clubs, and used for astronomical star parties and events -
such as International Astronomy Day on Saturday April 20th. These one page
info sheets are in addition to the brochure designed and written for NAMN by
Cathy Hall several years ago.
This gives clubs and event planners the option of using either the more
detailed 2-sided tri-fold brochure, or just printing off some of the one
page info sheets from our NAMN website.
We will be providing information about the NAMN handout material on our
website, so that you can get copies of this material for your Astronomy Day
activities, club events, and summer star parties! Or - just email our NAMN
Coordinator directly at meteors@comcastdot net for copies!
3. April Lyrids...
The Lyrids (LYR) are the first major shower of spring! They peak on April
22nd this year at 10.30 UT, with a ZHR rate of about 15 meteors per
hour. This means that if you are out under a clear dark country sky with
the radiant, the area in the sky where the meteors seem to come from,
directly overhead, then you should see on average, about 15 meteors
each hour with the unaided eye.
These are average velocity meteors, at about 49 km per second, and can be
seen from about April 16th to 25th. At maximum on the 22nd, the radiant
will be at 271 degrees, ie RA 18h 4.2m, Dec +34, which is approximately
halfway between the bright star Vega in Lyra and the star mu Herculis. To
see where this is on a star map, print yourself off a copy of our NAMN star
chart #3 at www.namnmeteors.org/charts.html. The chart shows the
constellations, RA and Dec, and star magnitudes. RA stands for Right
Ascension, and is basically longitude in the sky. Dec stands for
Declination, and is basically a measure of latitude in the sky. Star
magnitude means brightness - and we use the circled stars as a guideline for
estimating how bright the meteors are.
Meteor radiants don't stay put in the sky, though - they move from night to
night. This motion is not too noticeable over a day or two, but will add up
over a week. To see the movement of the Lyrid radiant across the sky, look
at the radiant map on the website of the IMO (International Meteor
Organization) at www.imodot net/calendar/cal01.html#Lyrids.
The IMO Handbook lists the Lyrid meteors as debris from Comet Thatcher,
C/1861 G1. This comet was discovered by A.E. Thatcher of New York on April
5th, 1861, and independently by Baeker of Nauen, Germany with the unaided
eye. It brightened to about magnitude 2.5, and had a tail of about 1-degree
in length. By comparison, the stars of the Big Dipper are slightly
brighter, at about magnitude 2, and the distance between the 'Pointer Stars'
of the Big Dipper is about 5 degrees. Comet Thatcher has an elliptical
orbit around the sun, and returns about every 415 years.
This meteor shower is an old one - in fact, the oldest for which
observations have been found. These meteors were seen in ancient China over
2000 years ago. The debris shed by Comet Thatcher is highly inclined in its
orbit, and doesn't pass near our solar system's planets. This means that
the 'meteoroid stream' has not been disrupted by the planets' gravity over
the years, and thus acts 'younger than its age'. The Lyrids have a short
period of maximum activity, only hours long, and clumps of debris can cause
interesting outbursts of meteor activity.
When you're out observing this April, just think - you are watching the
Lyrid meteors just like the ancient Chinese did 2000 years ago! They had...
no pocket tape recorders, no talking watches to mark time... but at least
they had very dark skies. Let us hear about your observations... now, what
would we do without email?
4. Other Spring Showers...
The Virginids (VIR) continue until about April 15th, as the radiant moves
along the path of the ecliptic in the sky. These meteors are almost slow,
with a velocity of about 30 km per second. ZHR rates are about 5 meteors
per hour. On April 10th, just before new moon, the radiant will be at 203
degrees, ie RA 13h 31.8m, Dec -7, which is about 4 degrees up to the left of
the star Spica in Virgo.
The pi Puppids (PPU) reach a maximum on April 23rd, with a radiant at 110
degrees, ie RA 7h 19.8m, Dec -45, which is about 15 degrees due south of the
star eta Canis Majoris, the bottom left foot star of Canis Major. These are
very slow meteors, at a velocity of about 18 km per second. ZHR rates are
variable, and have reached as high as 40 meteors per hour on occasion. This
meteor shower is debris from Comet 26P/Grigg-Skjellerup, discovered in 1902
by John Grigg of Thames, New Zealand, and J.F. Skjellerup of Cape of Good
Hope, South Africa.
The eta Aquarids, debris from Halley's Comet, start to appear in our skies
about April 19th, although won't reach a maximum until May 5th to 6th.
These are fast meteors, at a velocity of about 66 km per second. On April
20th, the radiant will be at 323 degrees, ie RA 21h 31.8m, Dec -7, which is
about a degree south of the star beta Aquarius, the star known as Sadalsuud.
Although rates will be about 60 per hour in May, rates in April will be low.
The Sagittarids (SAG) start to appear about April 15th, and will last until
about mid-July. This is a complex of radiants near the ecliptic, and is
believed to be the debris from a number of unknown bodies. Fireballs have
been associated with this shower. On April 20th, the Sagittarid radiant
will be at 227 degrees, ie RA 15h 7.8m, Dec -18, which is about 7 degrees
north of the star sigma Libra. These meteors are almost slow, with a
velocity of about 30 km per second, and the ZHR rates are about 5 meteors
per hour.
Besides recognized showers, there is also sporadic meteor activity in
April, about 7 meteors per hour, visible to the unaided eye. This
activity is comprised partly of random meteor activity and partly of
meteors that belong to long-ago, now untraceable showers.
Need some star charts to use for meteor observing? Print off a set from our
NAMN website at www.namnmeteors.org/charts.html
Want to do a bit of science while you are meteor observing? Check out our
NAMN Observing Guide at www.namnmeteors.org/guide.html
In April, the moon phases are as follows:
Thurs. Apr. 4 - last quarter
Fri. Apr. 12 - new moon - good observing weekend
Sat. Apr. 20 - first quarter - closest weekend to Lyrids
Sat. Apr. 27 - full moon
For use in judging the brightness of the meteors you see this month, the
magnitudes of the planets are as follows, to the nearest half magnitude:
Venus -4 low in the west, but very bright
Mercury -2 low in the west at midmonth, fading to -1 by months end
Jupiter -2 visible in Gemini
Saturn 0 visible in Taurus, low in the west
Mars 1.5 visible in Taurus, low in the west
From about April 18th on, there will be a nice group of bright planets all
in the western sky! And, on Tuesday April 16th, the planet Saturn will
appear to pass behind the moon, as visible from northwest North America,
northern Europe including the British Isles, northern Russia, Greenland, and
the Arctic Ocean.
Lastly, don't forget that we have a new comet in the sky this spring! Comet
Ikeya-Zhang was discovered on February 1st by Kaoru Ikeya of Japan and
Daqing Zhang of China, and independently about half a day later by Paulo
Raymundo of Brazil. It is brightening and should become visible as a
naked-eye comet in April, if you are out under dark country skies, away from
city lights. The comet is believed to be a return of the comet of 1661,
with a period of 340 years. The comet was low in the evening sky in March,
and is moving up into the pre-dawn morning sky in Andromeda in April. Print
yourself off a finder chart and coordinates from the Sky and Telescope
website at http://skyandtelescope.com
5. Upcoming Meetings...
July 21-26, 2002, Los Angeles, California USA...
The 65th annual meeting of the Meteoritical Society will be held at the
University of California in Los Angeles. Special sessions planned include
'Mars: Meteorites and Missions' and 'Chondrule and CAI origins'. For
information, check out www.lpi.usradot edu/meetings/metsoc2002
July 29-August 2, 2002, Berlin, Germany...
The Asteroids, Comets, Meteors 2002 Conference will be held in Berlin,
Germany. Topics that will be covered include comets, asteroids, meteor
showers, interplanetary material, collisions and impacts, NEO's (near earth
objects), the asteroid-meteorite connection, transitional objects, origin of
comets, and many other related topics. This is the 8th ACM conference in a
series, with a conference being held only every 3 years. It is being
jointly organized by the DLR Institute of Space Sensor Technology and
Planetary Exploration, the Max Planck Institute for Aeronomy, and the
Technical University of Berlin. There is a registration discount if you
register before May 1st. For details, contact J. Benkhoff at acm2002@dlrdot de
and check out the ACM 2002 website at http://berlinadmin.dlrdot de/SGF/acm2002
September 26-29, 2002, Frombork, Poland...
IMC 2002, the International Meteor Conference, will be held in Frombork,
Poland - land of Copernicus! This is the annual conference of the IMO, the
International Meteor Organization, and welcomes all meteor observers, both
amateur and professional. The conference is organized by CMW, the Polish
Comets and Meteors Workshop. Besides the talks and discussions, there are
many interesting sites to visit, such as the tower where Nicolaus Copernicus
made many of his observations and the Radziejowski tower with its
astronomical planetarium. For information, check out www.imodot net and
www.astrouwdot edu.pl/~olech/pkim/imc2002/imc.html. For specific questions,
contact Mariusz Wisniewski at pkim@astrouwdot edu.pl
For more information on upcoming astronomy meetings, see:
"International Astronomy Meetings List"
http://cadcwww.hia.nrcdot ca/meetings
6. For more info...
NAMN email: namn@atmob.org
NAMN website: www.namnmeteors.org
Mark Davis, meteors@comcastdot net
Goose Creek, South Carolina, USA
Coordinator, North American Meteor Network
Cathy Hall, chall@cyberusdot ca
Metcalfe, Ontario, Canada
Co-author, NAMN Notes
Lew Gramer, dedalus@alum.mitdot edu
Medford, Massachusetts, USA
Coordinator, Public Outreach
Owner/Moderator, 'MeteorObs'
Kevin Kilkenny, Mail4Meteors@aol.com
Staten Island, New York, USA
Coordinator, Fireballs and Meteorites
Back issues of NAMN Notes can be found on-line at the NAMN website
and in the MeteorObs archives at:
www.meteorobs.org
by selecting 'Browse Archive by Month'
To subscribe to the meteor email list or
To find out information on our weekly chat sessions:
Contact Lew Gramer at:
dedalus@alum.mitdot edu
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Here's to 'Clear Skies' for April...
April 2002 NAMN Notes co-written
by Mark Davis and Cathy Hall
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